Acceleration hesitation in 2nd/3rd

[f3nd3r]

Basically, when I push down on the gas pedal anywhere between 'just a little' to 'just before full throttle', it'll hesitate a bit all of the way through 2nd gear (no matter where it is on the tach). It also happens in 3rd but not quite as badly. Weird part is, there are no issues when I go full throttle (again, regardless of where it is on the tach) in any gear.

The car idles perfectly: about 800-900rpm to warm up, and then eases down to roughly 700 rpm. Of course, oil is new and clean, air filter brand new, spark plugs are solid. I haven't checked the injectors and I'd have no idea where to start with the throttle body, if that's a possibility of failure. I suppose I can't rule out any sort of modification that the previous owner may have done

The car is a 1987 325e (production date February 1987, not a SETA engine) with a 5 speed. Any insight would be great!

[smackley]

I am slowly learning that the e30 is notorious for several hesitation or missfire gremlins. So far in my 325iC, I have been chasing ghosts to find my source of symptoms. If you are dead set on learning a bit about your car and doing the work yourself, I highly suggest testing each system before replacing any parts at all.

Smoke test for vacuum leaks.

Fuel pressure gauge for fuel starvation problems.

Get a multimeter to test all sorts of electrical items (relays, TPS, ICV, etc)

Check your AFM to see if the resistance track is worn down on any spots

Swap your ECU if you can find a spare for testing

I think the 325e model has a CPS somewhere in the transmission vs the 'i' models that have them on the front of the motor.

***otherwise if googling/searching the forums on these possible culprits feels a bit intimidating...take it to a good mechanic. Save some time and money on throwing parts at the problem. Notice I said "good" mechanic. Someone who knows e30's well enough to sort it all out for you quickly.

I'll check in on your thread if you have questions, but I'm sure there are a thousand more qualified long time e30 owners who know better than I.

[frolf]

I'll weigh in.

Note: I am not commenting because I possess technical expertise. I do not. I am just another one of those "yeah my car did something similar" people.

My car hesitated in certain places all over the rev band. I replaced the AFM, no fix. Pulling my current AFM, I found it to track smoothly. I pulled the plugs (noticing that the plug wire on Cyl 1 was more or less just hanging on the plog) to find that 4 of the 6 were worn, and 2 of the 4 worn plugs actually had a small piece of debris between the electrodes. New plugs in, and the hesitation was gone. I then proceeded to replace plug wires, and cap and rotor (worn as well).

Of course, if you find that your AFM is done, I have a good one on my shop bench.